Blunted hemodynamic response and reduced oxygen delivery with exercise in anemic heart failure patients with systolic dysfunction

Anemic heart failure patients with systolic dysfunction are known to have reduced exercise capacity. Whether this is related to poor hemodynamic adaptation to anemia is not known. Peak exercise oxygen consumption (VO2) and hemodynamics at rest and peak exercise were assessed among 209 patients and compared among those who were (n=90) and were not (n=119) anemic. Peak VO2 was significantly lower among anemic patients (11.7+/-3.3 mL/min/kg vs 13.4+/-3.1 mL/min/kg; P=.01). At rest, right atrial pressure was higher (10+/-5 mm Hg vs 8+/-4 mm Hg; P=.02) and venous oxygen saturation lower (62%+/-8% vs 58%+/-10%; P<.01) among anemic patients. At peak exercise, anemic patients had a higher wedge pressure (27+/-9 mm Hg vs 24+/-10 mm Hg; P=.04). No significant differences in stroke volume, cardiac index, systemic vascular resistance, or oxygen saturation were noted between the 2 groups. In conclusion, the relative hemodynamic response to exercise among anemic heart failure patients appears blunted and may contribute to worse exercise tolerance.